Could it be a marvelous breakthrough, or just hot air?

Chinese scientists claim to have discovered a new clean energy source - simply by using dry air.

The discovery could have positive implications for parts of northern and western China, which have dry climate conditions, according to scientists at Tsinghua University.

"The breakthrough makes it possible to use dry air, instead of electricity, to cool down the water and the indoor air, and be applied at least to power large-scale air-conditioning equipment in office buildings," Jiang Yi, director of the university's architecture science department, who leads the research project, told China Daily.

For decades the world's scientists have been eyeing the potential of turning dry air into a useable energy.

The premise sounds simple enough: dry air absorbs moisture, and in doing so causes the air's temperature to drop.

Jiang said he was confident the energy could be widely applied, and that his team at Tsinghua was cooperating with a company in Xinjiang to produce air-powered air-conditioning equipment.

So far trials in some large buildings had been successful.

"Believe me, the air looks tranquil but it is imbalanced thermodynamically when it is dry," said Jiang, who is also an academic at the Chinese Academy of Engineering.

The process does not produce electricity, but provides a means to allow less reliance on electricity.

The technology could be compared to a solar hot water heater, whereby water is continuously heated as long as there is sunlight.

Currently the air-powered air conditioners can keep room temperature between 25 and 28 C, and scientists are still working to expand the range.

Zhang Fulin, the director of the science and technology office under the Ministry of Construction, said the breakthrough could have great implications for emission reductions.

(China Daily August 10, 2007)